Firebb15

So my 96 GT 4.6 auto is all original around 180,000 miles now, and it has been gradually getting worse with oil consumtion. It will blow blue smoke every time i leave a stop light when the engine is warm. It doesn't blow ANY when i start the car cold. I notice a lot of old cop cars (4.6 crown vics) in my area do the same thing. This seems very common, is this a valve seal issue, or something to do with the rings. Thanks for any info... Brian

GodAmGT00

Fire up a dry/wet compression test for a better results.. Sounds like valve seals though...


JT

cliffyk

Blue smoke on acceleration is usually worn rings/pistons/cylinders, leaving execssive oil on the cylinder walls that gets washed off by the incomiong charge and burned. Bad valve guides/seals generally make themsleves known on deceleration when the higher manifold vacuum sucks oil past the valve stem...[/align][/align]What weight oil are you running? Here in Florida I switch things over to 20W-50 after they get to 75k to 100k.[/align]

BBond007

My 96 is using about 1 qt every 1000 -1200 miles now.

I have an unknown amount of miles on the car. The odometer quit working several years ago.

Normally I don't see it smoke unless its been warmed up, then turned off and someone else starts it(you have to right behind the car to see it), and then its just a few puffs out both pipes. I really don't know where all the oil goes, but I do have new rear main seal and I never see oil spots.

I suppose I'm just going to keep putting oil in it for now, and maybe eventually look for a PI engine...

I might go for a low-mileage used engine vs a rebuild.

I have new shocks, struts, aluminum driveshaft, exhaust, clutch, t-45, etc... The engine is about the only thing left!

Oh well, good luck!

Firebb15

well i have been using 5w30 because that's what it says to use on a sticker under the hood...but i dont drive the car in winter here in michigan. So maybe i should step up to a thicker oil since i only drive the car in the summer. I hope that helps cut down on the smoke. 20w50 seems a little too thick, but i have never used it.I thought that stuff was used in diesels. Would that be ok, or should i go with a 10w40 or something? Thanks, Brian

Here's the car...
1996 gt 4.6 auto 180K
black leather
mach 460
H-pipe with no cats
larger throttle body
K&N
Reprogrammed the computer
and of course... cobra rims with 275/40s

BBond007

It never really gets real cold in Miami, so maybe its time to think about something else here as well. I'm overdue for an old change anyway.

I been using Moble 1 5w30. I see even now they have come out with some moble 1 high-mileage synthetic oils.

cliffyk

Back before manufacturer's started recommending these ****-thin oilsso they couldmeet CAFE standards 20W-50 was the standard recommended oil for 15°F to 120°F+ severe duty. Coldest it ever gets here is 35° or so, except for 2 or 3 times a year when we get a frost in the early morning.[/align][/align]I use 10W-30 synthetic in my '03 GT despite Ford's 5W-20 recommendation, if I ran dino I'd use 20W-50. I do use 20W-50 (Valvoline MaxLife) year-round in our other vehicles (my supercharged '2 Miata with 205k miles, and my wife's '96 RAV4 with 185k). The Miata's been running it since 111k, the RAV4 since 75k or so. I usually change it every 2000 to 2500 miles, never more than 3k.[/align][/align]My previous Miata, a 1990, run 20W-50 from 85k when I got it, until 315k when I sold it--it was supercharged from 235k 'til I sold it--at about 275k it developed a leak in therear seal, and used about 1/2 qt.between changes.[/align][/align]Oh, we had an '86 Corolla (purchased new for $4386) that went 285k on 20W-50 MaxLife, we traded it in on the RAV4 in '99 and got $1500 for it--leaked a bit but didn't burn a drop...[/align]